My JKU had a 285/75 on the back without issue and it's now on my daughter's Jeep. There aren't any vibrations, because I made sure to buy new snubbers and adjust them properly. I do have a Teraflex HD mount to install, but I have little concern about the durability and longevity of the OEM mount as long as the tire is properly supported by the snubbers on the tailgate (my reason for going with the Teraflex was because I got it for free and think I can modify it to get a better fitment for the backup camera).